Scalable Coherent Interface

SCI is an IEEE standard for shared-memory multiprocessing. The standard was approved in 1992. View the SCI Wikipedia article for more information on the interface's history. The article covers the cache-coherence portions of the IEEE standard.

Cache State Machine

The caches states cover two different dimensions: the cache's position in a linked list, and the modified state of a block.

• Head
• Mid
• Tail
• Only

• Clean
• Modified
• Fresh
• Valid
• Invalid

Directory State Machine

• Home
• Gone
• Fresh

References

• Wikipedia, Scalable Coherent Interface
• SCI